The 30-strong group formed in October 2005 will play three 45 minutes sets at this year's festival.
Previous performances by the choir include a set at Johnny Depp's bar, Le Mandalaray in Paris and the group have also collaborated with Duke Special for a version of 'Freewheel' (2007) and 'Ballerina' by Van Morrison (2008).
Band members hail from a variety of places including Poland, Switzerland, America, France, Australia and Ireland.